source: mainline/uspace/lib/c/generic/thread.c@ d4c472b

/*
 * Copyright (c) 2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 */

#include <thread.h>
#include <libc.h>
#include <stdlib.h>
#include <libarch/faddr.h>
#include <kernel/proc/uarg.h>
#include <fibril.h>
#include <str.h>
#include <async.h>
#include "private/thread.h"

#ifndef THREAD_INITIAL_STACK_PAGES_NO
#define THREAD_INITIAL_STACK_PAGES_NO   2 
#endif

/** Main thread function.
 *
 * This function is called from __thread_entry() and is used
 * to call the thread's implementing function and perform cleanup
 * and exit when thread returns back.
 *
 * @param uarg Pointer to userspace argument structure.
 *
 */
void __thread_main(uspace_arg_t *uarg)
{
        fibril_t *fibril = fibril_setup();
        if (fibril == NULL)
                thread_exit(0);
        
        __tcb_set(fibril->tcb);
        
        uarg->uspace_thread_function(uarg->uspace_thread_arg);
        /* XXX: we cannot free the userspace stack while running on it
                free(uarg->uspace_stack);
                free(uarg);
        */
        
        /* If there is a manager, destroy it */
        async_destroy_manager();
        fibril_teardown(fibril);
        
        thread_exit(0);
}

/** Create userspace thread.
 *
 * This function creates new userspace thread and allocates userspace
 * stack and userspace argument structure for it.
 *
 * @param function Function implementing the thread.
 * @param arg Argument to be passed to thread.
 * @param name Symbolic name of the thread.
 * @param tid Thread ID of the newly created thread.
 *
 * @return Zero on success or a code from @ref errno.h on failure.
 */
int thread_create(void (* function)(void *), void *arg, const char *name,
    thread_id_t *tid)
{
        char *stack;
        uspace_arg_t *uarg;
        int rc;

        stack = (char *) malloc(getpagesize() * THREAD_INITIAL_STACK_PAGES_NO);
        if (!stack)
                return -1;
                
        uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t));
        if (!uarg) {
                free(stack);
                return -1;
        }
        
        uarg->uspace_entry = (void *) FADDR(__thread_entry);
        uarg->uspace_stack = (void *) stack;
        uarg->uspace_thread_function = function;
        uarg->uspace_thread_arg = arg;
        uarg->uspace_uarg = uarg;
        
        rc = __SYSCALL4(SYS_THREAD_CREATE, (sysarg_t) uarg, (sysarg_t) name,
            (sysarg_t) str_size(name), (sysarg_t) tid);
        
        if (rc) {
                /*
                 * Failed to create a new thread.
                 * Free up the allocated structures.
                 */
                free(uarg);
                free(stack);
        }

        return rc;
}

/** Terminate current thread.
 *
 * @param status Exit status. Currently not used.
 *
 */
void thread_exit(int status)
{
        __SYSCALL1(SYS_THREAD_EXIT, (sysarg_t) status);
        
        /* Unreachable */
        while (1);
}

/** Detach thread.
 *
 * Currently not implemented.
 *
 * @param thread TID.
 */
void thread_detach(thread_id_t thread)
{
}

/** Join thread.
 *
 * Currently not implemented.
 *
 * @param thread TID.
 *
 * @return Thread exit status.
 */
int thread_join(thread_id_t thread)
{
        return 0;
}

/** Get current thread ID.
 *
 * @return Current thread ID.
 */
thread_id_t thread_get_id(void)
{
        thread_id_t thread_id;

        (void) __SYSCALL1(SYS_THREAD_GET_ID, (sysarg_t) &thread_id);

        return thread_id;
}

/** @}
 */